1. Technical Field
The invention relates to medical devices. More particularly, the invention relates to a method and apparatus for surgical electrocautery.
2. Description of the Prior Art
Electrocauterization is the process of cauterizing, coagulation, and/or destroying tissue with electricity. A small probe with an electric current running through it is used to cauterize (burn or destroy) the tissue. The procedure is frequently used to divide tissue structures in a fashion which is hemostatic (seals blood vessels, thereby preventing bleeding). See, for example, Y. C. Jou, M. C. Cheng, J. H. Sheen, C. T. Lin, P. C. Chen, Electrocauterization of bleeding points for percutaneous nephrolithotomy, Urology 64(3):443-6 (September 2004). The use of electrocautery has been extremely beneficial for the performance of surgical procedures, such as hysterectomy (the surgical removal of the uterus), where relatively long spans of tissue must be sealed and divided to remove the organ. Experiments to date with a set or sets of single continuous electrode pairs running the length of a device's long jaws have resulted in inconsistent arterial sealing and tissue cauterization. These inconsitent outcomes are likely due to inconsistent electrode contact with the long (1-15 cm), complext tissue sheets. That is, while the electrodes and their backing surfaces are rigid, the tissue sheets are highly variable in their thickness and composition, given that the tissue sheets frequently contain arteries, veins, nerves, ligaments, lymphatics, etc.
To achieve sealing along the entire tissue length, the electrode or its backing surface must be conformable, but also must still be able to deliver adequate force to produce an adequate electrocautery seal. While a compressible material, such as a polymer or foam, can work, these materials do not transfer consistent force because the compressed regions of the material exert higher force than in those regions where tissue is thinner, and the material is less compressed.
One solution in addition to the incorporation of conformable electrodes is to create multiple electrodes, where each electrode may have a different sealing profile, either from an electric power or energy standpoints, or from a conformability standpoint; and/or electrodes with a conformal surface, either under the electrode or as a standoff to the sides of the electrodes. While this approach is promising, there is still more to do.
It would therefore be advantageous to provide a surgical electrocautery method and apparatus that achieves sealing along the entire tissue length, and that also is able to deliver adequate force to produce an effective electrocautery seal.